18/07/2024 Erik Kusch
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Erik Kusch
Senior Engineer
Machine Readable Nature Research Group (MANA)
Department of Research and Collections
Natural History Museum
University of Oslo
18/07/2024 Erik Kusch
INTEGRATING CO-
EXTINCTION RESILIENCE
MECHANISMS
Updating Projections of Ecological Networks
ISEC 2024
18/07/2024 Erik Kusch
2Extinction Cascades & Proxies of Threat
Proxies for Risk of Primary Extinction
ISEC 2024
Topology
Centrality
...
Climate Projections
Safety Margins
...
Realism Worst & Best Cases
Primary Extinction(s)
P1 P2 P3
A1 A2 A3
P4
Primary Extinction
Secondary Extinction(s)
P1 P2 P3
A1 A2 A3
P4
Secondary Extinction
Legend
Initial Network
P1 P2 P3
A1 A2 A3
P4
Unaffected Node
Unaffected Link
Loss of Link(s)
P1 P2 P3
A1 A2 A3
P4
Lost Link
What about secondary extinction risk?
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Link-Loss-Sensitivity
% of combined initial interaction
magnitude a species requires for
continued existence
Rewiring Probability
Thresholds
Probability threshold which a
potential interaction needs to
exceed for establishment
Secondary Extinction Risk: Network Resilience
Link-loss sensitivity and rewiring probability thresholds establish
two-dimensional landscapes of network resilience.
Post-Extinction Network
Contemporary Rworkflows fail to
incorporate link-loss sensitivity or
rewiring thresholds.
ISEC 2024
P1 P2 P3
A1 A2 A3
P4
P1 P2 P3
A1 A2 A3
P4
P1 P2 P3
A3
P4
0.2 0.8 0.4 0.7
Link Probabilities
Contemporary Extinction
Cascade Analyses
18/07/2024 Erik Kusch
4NetworkExtinction –Extinction Resilience in R
NetworkExtinction supports:
Extinction Cascade Simulations
Static order:
Ordered
Random
Dynamic order
Mostconnected
Leastconnected
Extinction Cascade Visualisations
Supported Network Types:
Mutualistic
Trophic
Fully integrates:
Link-loss sensitvity
Rewiring Probability Thresholds
Defined either:
Whole-network
Individual nodes
ISEC 2024
18/07/2024 Erik Kusch
5Study Design & Primary Extinction Risk
Network Data
Plant-Frugivory Network Collection (Fricke et al., 2022)
406 networks
Extinction Risk Proxies
Networks for Analysis
81 networks
Species Richness
Interaction Strength Variation
ISEC 2024
rgbif
GBIF
1982-1999 Presence Records
1724 species
CMIP6 Projections KrigR 1982-1999
2081-2100
SSP245 & SSP585
Climate Preferences & Niches
Climate Safety Margins
igraph
Centrality
Species
… … … … …
… … … … …
… … … … …
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Functional Expressions for Target Species
60,047 records, 1724 species
Subset for 1724
target species
identities
Probability Matrices of Interactions between Target Species
Potential Networks & Rewiring Probability
Functional Trait Data
Functional Trait Expressions (Fricke et al., 2022)
124,179 records, 4715 species
Plant Plant-Trait 1 Plant−Trait ... Animal Animal−Trait 1 Animal-Trait … Link Presence Network ID
… … … … … … … …
… … … … … … … …
… … … … … … … …
Rewiring Potential Identification
Network 1 Plant A Plant B Plant …
Animal A … … …
Animal B … … …
Animal … … … …
Network 2 Plant A Plant B Plant …
Animal A ………
Animal B ………
Animal … … … …
Network … Plant A Plant B Plant …
Animal A … … …
Animal B … … …
Animal … … … …
randomForest
NetworkExtinction
ISEC 2024
Centrality
Climate Safety Margins
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SSP245
SSP585
Drivers of Threat to Global Ecological Networks
ISEC 2024
Climate Safety Margins
Climate Safety Margins
Centrality
Centrality
Climate Safety Margins
Centrality
Centrality
Centrality
Climate Safety Margins
Centrality
Centrality
Centrality
1. Biodiversity loss through climate-change
extinction cascades intermediate to centrality
extinction cascades.
3. Extinction cascade resilience
mechanisms affect projected
biodiversity loss greatly.
4. The effect of rewiring probability
thresholds (RPT) is greater than that of
link-loss sensitivity (LLS).
2. Action to avoid high-
emission scenarios is
vital to avoiding
biodiversity loss
following extinction
cascades.
18/07/2024 Erik Kusch
8Empirical Network Resilience Landscapes
Network resilience landscapes demonstrate variation of
future ecosystem scenarios
Contemporary practices fail to explore these
Contemporary analysis assumptions:
Secondary extinction when all links are lost
No rewiring
Rewiring Probability Threshold
Relative Loss of Species
Link-Loss Sensitivity
SSP245
ISEC 2024
5. Contemporary simulations of extinction cascades likely underpredict
future biodiversity loss.
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9Outlook & Next Steps
ISEC 2024
Rewiring Probability Threshold
Relative Loss of Species
Link-Loss Sensitivity
SSP245
?
What Now?
Identify realistic ranges of Link-
Loss Sensitivity and Rewiring
Probabilities and Thresholds.
Particularly, a deeper understanding of rewiring capabilities and how to
enhance them would be invaluable to safeguard against biodiversity loss.
